The present invention relates to an apparatus and a method for performing information recording using light (including various types of electro-magnetic radiation beams) with respect to a recording medium which stores information, and in particular, to an improved developing process for recording media.
Recording apparatus with respect to recording media which store information include for example, that shown in FIG. 1. In this figure, a recording medium 10 is configured with a recording member 16 laminated onto a transparent substrate 12 via a transparent electrode 14. A write head 20 is configured with a photoconductive member 26 laminated onto a transparent substrate 22 via a transparent electrode 24. Then, the recording medium 10 and the write head 20 are arranged so that the photoconductive member 26 is opposite the recording member 16.
Between the transparent electrodes 14 and 24 there is a drive power source 30 connected via a switch 32. To the side of the transparent substrate 22 of the write head 20 there are arranged an optical shutter 34 and a taking lens 36. In addition, there is another drive power source 40 which impresses a voltage to the switch 32 and the optical shutter 34 via a switch 38 so that the switch 32 and the optical shutter 34 are operated.
Glass substrates for example, are used as the transparent substrates 12 and 22. In addition indium-tin oxide for example, is used as the transparent electrodes 14 and 24. The recording member 16 is capable of having a charge image formed on its surface for a long time in accordance with an impressed electric field and of photomodulation according to the charge image. For example, it is possible to apply silicone resin, liquid crystal, lead lanthanum zirconate titanate, an electrochromic material or the like to the recording member 16. A polymer-dispersed liquid crystal memory is also applicable to the recording member 16. The photoconductive member 26 is made of a photoconductive material such as a-Si or the like so that a charge image corresponding to information is formed when light carrying the information to be recorded is irradiated to the photoconductive member 26.
The following is an outline description of the recording operation in the recording apparatus having the configuration described above. When the switch 38 is switched to its ON state, a voltage of the drive power source 40 is impressed to the switch 32 and the optical shutter 34 to operate. Because of this, a voltage of the drive power source 30 is impressed across the transparent electrodes 14 and 24, and the optical shutter 34 opens, so that light carrying image information of an object 42 is irradiated to the photoconductive member 26 of the write head 20 via the taking lens 36 and the optical shutter 34. By this, the photoconductive member 26 exhibits conductivity distribution corresponding to the intensity of the irradiated light.
When this occurs, the drive voltage which is impressed across the transparent electrodes 14 and 24 is fractionally and variably impressed to the recording member 16 in accordance with the conductivity distribution of the photoconductive member 26. A charge image corresponding to the image information of the object 42 is thus formed on the surface of the recording member 16. By this, the image information of the object 42 is recorded as changes in the variation of optical transmittivity on the recording member 16 if including liquid crystals.
FIG. 2 shows the characteristics graph of the recording operation described above. First, the relationship between the optical transmittivity of the irradiated light and the impressed voltage in the recording member 16 is as shown by the graph GA. In addition, the relationship between the exposure amount in the photoconductive member 26 and the voltage which is impressed to the recording member 16 by the exposure amount is as shown by graphs GB and GC. B1 and B2 are the dark potential.
The exposure range with respect to the photoconductive member 26 is made EW. In the case of the graph GB, the voltage which is impressed to the recording member 16 by the photoconductive member 26 is in agreement with the variation of the optical transmittivity (as shown by dotted line arrows FA and FA). Because of this, the optical image of the object 42 is favorably recorded to the recording member 16.
However, when the characteristics of the photoconductive member 26 is as shown by the graph GC, the voltage which is impressed to the recording member 16 by the photoconductive member 26 has the range shown by dotted line arrows FB and FB. More specifically, the voltage impressed with respect to the recording member 16 does not attain a threshold value SV, and there is no variation of the optical transmittivity on the recording member 16. Therefore, when a photoconductive member with a low dark potential is used there is no recording of the optical image of the object 42.
Accordingly, a photoconductive member having a high dark potential could be used but when such a photoconductive member is used, it is likely to generate unevenness in the dark potential and thus there is the resultant influence of shading due to the unevenness.